Recipe 20.14. Sharing IMAP Folders

20.14.1 Problem

You want to set up shared folders on your IMAP server, and let your users create their own shared folders.

20.14.2 Solution

Use Courier's maildirmake command. First, as root, create a shareable Maildir with the big -S flag:

# maildirmake -S /var/mail/sysadmins

Then create a shareable folder (yes, these are plain old Linux directories, but Courier calls them folders) in the Maildir with the little -s flag. write gives read/write permissions to everyone:

# maildirmake -s write -f reports /var/mail/sysadmins

You can add another folder, with read permissions only, using:

# maildirmake -s read -f policies /var/mail/sysadmins

Note that maildirmake creates dot, or hidden, directories:

# ls -a /var/mail/sysadmins

. .. .reports .policies  cur  new  tmp

Permissions can be fine-tuned on the individual folders, just like with any Linux directory. (See Recipe 9.7 to learn how to adjust permissions on shared directories.) To remove shared folders, just delete them.

Users can also share folders. Their shared folders remain in their own home directories:

$ maildirmake —add images=/var/mail/sysadmins $HOME/Maildir

Users may "unshare", or break the link to the shared directory, with —del:

$ maildirmake —del images  $HOME/Maildir

20.14.3 Discussion

If you want a full-blown groupware/email server, it is possible to assemble all the pieces by hand from free/open source components. There are also a number of prefab Linux groupware packages available, some free of cost, some commercial. This is a small sampling—there are many more in various stages of development:

PHP GroupWare

http://www.phpgroupware.org

OpenGroupware

http://www.opengroupware.org

The Kolab Project

http://kolab.org

SuSE OpenExchange

http://www.suse.com

SKYRiX Groupware

http://www.skyrix.com

Novell Linux

http://www.novell.com/linux

20.14.4 See Also

• maildirmake(1)